Metal amidino precursor and preparation method thereof
The one-pot method for preparing metal amidine-based precursors solves the problems of difficult synthesis and low yield, achieving high-yield and high-purity preparation of metal amidine-based precursors, simplifying the process and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-04-14
AI Technical Summary
Existing metalmidine-based precursors are difficult to synthesize, have low yields, and are costly.
A one-pot method was used to prepare metal amidine precursors by reacting alkyl diimines with metal complexes or hydrides, followed by reaction with MClx. Specific solvents and temperature control were used to avoid violent reactions and simplify the process.
This method enables the preparation of high-yield, high-purity metal amidine-based precursors, simplifying the synthesis process and reducing costs.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor materials, and more specifically to a metal amidine-based precursor and its preparation method. Background Technology
[0002] Metal-amidine-based precursors are a class of special organometallic compounds with important applications in semiconductor thin film deposition (such as CVD and ALD processes). Their core characteristic is the formation of a stable structure through coordination of amidine ligands with metal ions. These precursors are used to deposit High-K dielectric layers and metal gate materials, meeting the requirements of advanced processes for dielectric constant and leakage current control. Therefore, the importance of metal-amidine-based precursors is self-evident.
[0003] In perovskite applications, metalmidyl precursors can enhance film stability through alloying strategies. Metalmidyl precursors optimize film morphology through ligand design (such as TTFA and pentamidine), reducing exciton binding energy and nonradiative recombination while improving thermal stability. A team at Nankai University modulated the crystallization kinetics of two-dimensional perovskites using formamidinyl organic semiconductor ligands (such as TTFA). TTFA ligands lower the nucleation energy barrier by forming larger clusters, inducing directional growth and significantly improving film quality, achieving a device efficiency of 19.41%. A team led by Wang Rui at Westlake University discovered that pentamidine can control the orientational nucleation of formamidinium lead-iodide perovskite, suppressing non-optically active crystalline phases, resulting in an efficiency of 25.4% for small-area devices and 21.4% for large-area modules. However, these amididine-based complexes currently face challenges such as difficult synthesis, low yield, and high cost.
[0004] Therefore, providing a method for producing a metal amidine-based precursor that is simple to process, has high yield, and high purity is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, the present invention provides a one-pot method for preparing metal amidine-based precursors. The reaction process requires no additional purification and is simple.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A metalmidine-based precursor, the metalmidine-based precursor having a structure as shown in Formula 1: ; General Formula 1 R3 is independently selected from hydrogen, C1 to C5 straight-chain or branched alkyl groups, and M is a main group metal, transition metal, or lanthanide metal. R1 and R2 are each independently selected from at least one of hydrogen, C1 to C10 straight-chain or branched alkyl, C3-C8 cycloalkyl or cycloalkenyl; x takes values from 0.7 to 6.
[0007] Furthermore, M is any one of Mg, Al, Ca, Cr, Mn, Zn, In, W, La, Er, and Tb.
[0008] The present invention also provides a method for preparing the above-mentioned metal amidine-based precursor, characterized in that the metal amidine-based precursor is obtained by reacting a substrate with an alkyl diimide and then reacting it with MClx, wherein the substrate is an alkyl metal complex or a metal hydride; The substrate has the general formula R3-M0, where M0 is any one of alkali metals or alkaline earth metals. Its preparation process is as follows:
[0009] The preparation steps are as follows: (1) Under a protective atmosphere, alkyldiimide is added to the reaction solvent, and then the substrate is added to react and a reaction solution is obtained; (2) MClx was added to the reaction solution to carry out the reaction and the metal amidine precursor was obtained.
[0010] Furthermore, the protective atmosphere described in step (1) is a nitrogen atmosphere or an argon atmosphere.
[0011] Furthermore, in step (1), the reaction temperature between the substrate and the alkyldiimide is -40℃ to 0℃, and the reaction time is 0.5-6h.
[0012] The beneficial effect of adopting the above-mentioned further solutions is that the above-mentioned solutions of the present invention can effectively prevent the reaction from being too violent, while ensuring that the reaction is sufficient.
[0013] Furthermore, the reaction solvent is any one or a mixture of n-hexane, tetrahydrofuran, diethyl ether, and dioxane.
[0014] The beneficial effect of adopting the above-mentioned further solutions is that the solvent of the present invention can stabilize the intermediate and improve the purity of the product.
[0015] Furthermore, the molar ratio of MClx, substrate, and alkyldiimide is 1:(1.4-7):(2.5-9).
[0016] Furthermore, in step (2), the reaction temperature is 20-50℃ and the reaction time is 12-24h.
[0017] The beneficial effect of adopting the above-mentioned further solutions is that the solutions of the present invention can effectively improve the reaction yield.
[0018] Furthermore, the reaction process in step (1) is shown in Equation 1:
[0019] Formula 1 Furthermore, the reaction process in step (2) is shown in Equation 2:
[0020] Formula 2 Furthermore, the reaction also includes a filtration and sublimation step after completion.
[0021] The beneficial effects of this invention are as follows: This invention uses alkyl metal complexes or metal hydrides to react with alkyl diimides to prepare amidine lithium salts, which are then further reacted with MClx to obtain metal amidine complexes. The product of this invention is prepared using a one-pot method, requiring no purification in the intermediate process, simplifying the reaction and solving the problem of complex synthesis processes for metal amidine complexes. Detailed Implementation
[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] Example 1 A method for preparing a metal amidine-based precursor, specifically a method for preparing tris(N,N'-diisopropylmethylamidinyl)indium(III) in this embodiment, includes the following steps:
[0024] (1) Under nitrogen atmosphere protection, weigh diisopropyl diimine (206.0 g, 1.6 mol), dissolve it in 3 L of diethyl ether, add lithium hydride (11.3 g, 1.4 mol) at -30 °C, react for 4 h to obtain amidine salt reaction solution.
[0025] (2) Add InCl3 (74g, 0.4mol) to the reaction solution, react at 25℃ for 12h, filter, dry the filtrate under vacuum to obtain 178g of white solid, sublimate the white solid under vacuum to obtain 151g of white solid, and calculate the yield as 76.0%. The purity of the ICP test is 5N.
[0026] Example 2 A method for preparing a metal amidine-based precursor, specifically a method for preparing bis(N,N'-diisopropylethamidinyl)magnesium(II) in this embodiment, includes the following steps:
[0027] (1) Under nitrogen atmosphere protection, weigh diisopropyl diimine (206.0 g, 1.6 mol), dissolve it in 3 L of diethyl ether, add methyl lithium (1.6 M in Et2O, 875 mL, 1.4 mol) at -30 °C, react for 4 h to obtain amidine salt reaction solution.
[0028] (2) MgCl2 (57.1g, 0.6mol) was added to the reaction solution and reacted at 25℃ for 12h. After filtration, the filtrate was dried under vacuum to obtain 160g of white solid. The white solid was sublimated under vacuum to obtain 135g of white solid. The yield was calculated to be 80.9%, and the purity was 5N according to ICP test.
[0029] Example 3 A method for preparing a metal amidine-based precursor, specifically a method for preparing tris(N,N'-diisopropylbutamine)yttrium(III) in this embodiment, includes the following steps:
[0030] (1) Under nitrogen atmosphere protection, weigh diisopropyl diimide (206.0 g, 1.6 mol), dissolve it in 3 L of diethyl ether, add n-butyllithium (1.6 M in Et2O, 875 mL, 1.4 mol) at -30 °C, react for 4 h to obtain amidine salt reaction solution.
[0031] (2) Add YCl3 (78.2g, 0.4mol) to the reaction solution, react at 25℃ for 12h and then filter. After vacuum drying of the filtrate, 178g of white solid was obtained. The white solid was sublimated under vacuum to obtain 134g of white solid. The yield was calculated to be 71.4% and the purity was 5N according to ICP test.
[0032] Comparative Example 1 A method for preparing an organolanthanum precursor (a type of metal amidine-based precursor) includes the following steps:
[0033] (1) Under nitrogen atmosphere protection, weigh N,N-diisopropylmethylamidine (205.2 g, 1.6 mol), dissolve it in 3 L of diethyl ether, add n-butyllithium (1.6 M in Et2O, 1000 mL, 1.6 mol) at -30 °C, react for 4 h to obtain amidine salt reaction solution.
[0034] (2) Add InCl3 (74g, 0.4mol) to the reaction solution, react at 25℃ for 12h and then filter. After vacuum drying of the filtrate, 158g of white solid was obtained. The white solid was sublimated under vacuum to obtain 110g of white solid. The yield was calculated to be 55.4%. The purity was 4N according to ICP test. The metallic impurity Li was extremely difficult to remove.
[0035] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A metal amidine-based precursor, characterized in that, The metal amidine-based precursor has the structure shown in Formula 1: ； General Formula 1 R3 is independently selected from hydrogen, C1 to C5 straight-chain or branched alkyl groups, and M is a main group metal, transition metal, or lanthanide metal. R1 and R2 are each independently selected from at least one of hydrogen, C1 to C10 straight-chain or branched alkyl, C3-C8 cycloalkyl or cycloalkenyl; x takes values from 0.7 to 6.
2. The metal amidine-based precursor according to claim 1, characterized in that, M is any one of Mg, Al, Ca, Cr, Mn, Zn, In, W, La, Er, and Tb.
3. A method for preparing the metal amidine-based precursor according to claim 1 or 2, characterized in that, The metal amidine precursor is obtained by reacting a substrate with an alkyl diimide and then with MClx, wherein the substrate is an alkyl metal complex or a metal hydride; The substrate has the general formula R3-M0, where M0 is any one of alkali metals or alkaline earth metals. Its preparation process is as follows: The preparation steps are as follows: (1) Under a protective atmosphere, alkyldiimide is added to the reaction solvent, and then the substrate is added to react and a reaction solution is obtained; (2) MClx was added to the reaction solution to carry out the reaction and the metal amidine precursor was obtained.
4. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, The protective atmosphere mentioned in step (1) is a nitrogen atmosphere or an argon atmosphere.
5. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, In step (1), the reaction temperature of the substrate with the alkyldiimide is -40℃ to 0℃, and the reaction time is 0.5-6h.
6. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, The reaction solvent is any one or a mixture of n-hexane, tetrahydrofuran, diethyl ether, and dioxane.
7. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, The molar ratio of MClx, substrate and alkyldiimide is 1:(1.4-7):(2.5-9).
8. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, In step (2), the reaction temperature is 20-50℃ and the reaction time is 12-24h.
9. The method for preparing a metal amidine-based precursor according to claim 3, characterized in that, The reaction also includes a filtration and sublimation step.